Clumping bamboo can be widely grown in tropical areas of the world. The structure of such bamboo is strikingly different from that of many other plants. The trunk of the plant is called the "culm." "Nodes" exist at various distances along the culm. In some varieties of bamboo, the culm may grow to be several tens of feet in length. The diameter of the culm decreases from a maximum diameter at the earth to a small diameter at the tip. The larger diameter portions of a culm may find many applications, such as described in my U.S. Pat. No. 5,675,951 and U.S. Pat. No. 5,636,577. The smaller segments of large culms or smaller diameter culms, however, require other applications taking advantage of the unique structural characteristics of bamboo. Among these characteristics is a tough, hard outer skin.
Bamboo culms having a diameter from about 0.5 inches to about 1.5 inches are strong, flexible and elastic. When flexed, the culm bends and will not break as easily as wood. When flexed for a short period of time, it will return to its original configuration. Bamboo is also easily treatable with chemicals. Treatment methods can be used on bamboo which make it easier to treat than wood, because the fibers in bamboo run in the same direction. For example, a treatment method for bamboo is the Boucherie/Sap Displacement Method. A disadvantage of bamboo in many applications is the growth habit of the plant. Immature culms from clumping bamboo often grow in arcs, because the culms not in the center of a clump grow outwardly to receive more sunlight. Particularly the Dendrocalamus Strictus and the Jimba varieties grow in a curve; however, the curvature is generally in one plane.
If the clumps in which tropical bamboo grows are placed optimal distances apart, straight culms are expected when clumps grow large and the culms are 40 to 60 feet tall. Such culms will be several inches in diameter at the bottom. During immaturity, however, the clumps are smaller and the diameter of the culms is much smaller. Therefore, culms in the size range of about 0.5 to about 1.5 inches can be obtained either from young bamboo or from the upper reaches of mature bamboo culms. The immature culms, particularly, are likely to be curved.
Once established, bamboo replenishes itself very rapidly. Therefore, fully developed bamboo culms can be cut every two to three years. In even less time, culms in the 0.5 to 1.5 inch diameter can be cut from immature clumps. One-half to one-third of the immature culms can be cut each year. This thinning of a clump of bamboo causes larger culms to develop. Therefore, in the process of growing large culms for other applications, a supply of culms in the 0.5 to 1.5 inch diameter is available. There is need for methods and products to utilize this bamboo and to take advantage of its unique properties.